| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that a conventional dual damascene copper wiring formation method is provided to open a silicon nitride film on lower layer wiring by etching, and when it is left in atmosphere in that status, ammonia is eluted from the silicon nitride film, and copper wiring in the lower layer is dissolved, and any disappearing section is generated, and any reaction product is formed on the opening face, and inter-upper/lower layer wiring connection failure is generated. SOLUTION: A silicon nitride film 103 and an inter-layer insulating film 102 are formed on lower layer wiring 101, and contact and trench dry etching is carried out. Then, etching is carried out by gas containing SiH<SB>4</SB>and oxygen and phloro-carbon when the silicon nitride film 103 is etched. As a result, an SiO<SB>2</SB>protecting film 108 is formed on the side wall of the silicon nitride film 103 so that the elution of ammonia from the silicon nitride film 103 can be suppressed, and that inter-upper/lower wiring connection failure can be prevented. COPYRIGHT: (C)2005,JPO&NCIPI
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